Belt-shifting mechanism



I June 22 1926.

M. E. INFIORATI, JR BELT SHIFTING MECHANISM 2 Sheets-Sheet l f. A/1y 6 2 Sheets-Sheet 2 M. E. INFIORATI, JR

BELT SHIFTING MECHANISM original Filed sept. 12

June 22 19.26.

4h S www@ d Ifw wmd. am IW@ a/ZEO E @mm2 Patented June 22, 1926.

"U`N'-ITED STAT-LES MATTEO E. INFIORATI, JR., F DAYTON,

COMPANY, 'OF NEV LONDON, CONNECTICUT, A CORPORATION OF ll/1:15.11@E.`

BELT-SHIFTING `MECHANIS1VL This invention --relates to improvements in `Abelt shifting mechanism, whereby the operation of av machine may Abe automatically stopped at any predetermined point. It Vis .s `particularly applicable to terminate ythe Etravel of a'reciprocating-machinein-both directions. As 'illustrated lit isapplied toa broaching machine fhaviing a pair of reciproeating heads arrangedwto Ymove simultanein ously in opposite directions `of travel, being adivision of subject matter disclosed Ibut Vnot claimed 'in my pending application -for patent Serial No.V 587,677. Howeven as the utility of thisbelt shifting means relates to i5 "the driving lmeans :ratherithan to the nature 'of work done zby lthe *,machine, Iit is obvious that it may be applied also ito other kinds of machines. Y

`Among fthe iobjects is the provision of a @tu reversible belt drive inTwhi'ch yonly single widthbeltepulleys yneed be used, and only 'three `of these areaequired. *For starting, "abelt 4is shifted-by the operator,^to thesingle vdrive pulleypbut while itsreturn iszeffected ,471 by the travel of :the machine, the speed of its return is not necessarily vthat at which thetraveling element of the machine'may be moving, `,but may fif desired bemore gentle, the speed of action .in Sthis respect being con- .1c trolllcdby'the strength selected for a spring. Each fbelt, unless held positively on the drive pulley, tends always to return to and i stay on its own 'loose pulley. Other features `will be noticed in Ithe description which :ifi follows.

y nThe yembodiment of the invention herein illustrated comprises fthree single width belt Epulleys mounted adjacentone another on a drive shaft, `the middle onebeingfast onthe 4H shaft and the others loose thereon. vThe driving belts, runningin opposite directions on the outer pulleys when the machine `is idle, are selectively shifted tothe inner pulley by a system of linkage operated manv if ually. Between' 'the hand'lever` and the belt shifting leversiofithis linkage are elements which'j forml a rigid connection --.when the fbelt is being shifted to driving position,for while it is held there, but which, upon the shifting [of the hand leverV either manually or auto- An'iatically by -dogs attached to fthe traveling element to release the belt, form a lost motable l2.

, Original application filed` September 12, 1922, Serial No. 587,677. )Divided and this applcationvled August 7,1924. Serial 730,555. y

Vtion connection which permits thev bui-'den ofactually returning the belt vto its idle pnl.

ley 'to be undertaken andzborne by aspring device attachedto both belt ishiftinglevers. This spring meansk always tends yto ymove the Jbelts toward lor hold them upontheir vidle Vhen lordinarily .shiftingfga ,belt

pulleys. from driving `to idle position,f the spring ,applies a `steady pullona,belt,tomove1it at uniform speed `irrespective of Ithe-.speed .at

which the hand lever is thrown. If, however, the belt which fhasbeen ,upon its idle` pulley, while athe other beltwisdrivingpis -1nanually shifted :toward driving ,position before the spring has .whollyedected'the .removal of the other -belt from the drive'pulley, the spring :w-i-ll be further elongatedaand its pull upon lthe retreating belt .increased vto the end thatvthe Shifting of 1.the ,latter fis hastened, thus getting it out of the. wayof 'the belt that-is being movedhto'driving @position.` y

"Tn theaccompanying drawings `the -machine to which the belt shifting ,mechanism is applied typifiesany sort ofi-machinehai7- ing a traveling element whose ymovements can be utilized 'to effect automatically theactuation of the belt shifting mechanism to stop the machines operations. It `is intended that the patent shall cover @by suit- :able expression in the appended claims whatever features of patentable i -novelty exist in the invention disclosed.

In ythe drawings:

Figure l is a side elevation of a machine partly vin section, embodying fthebelt shifting `mechanism of the presentinvention;

Figure 2 is an elevation taken .fon 'line 2 2 of Figure 1;

Figure 3 lisa plan View; and Figures i and 5 are side-elevationss'howing different positions of thefbelt shifting mechanism.' l

Referring yto the drawings, ithe particular machine :illustrated iswa` push press ybroachying machine having. traveling breach .heads 10, Vguided on ways 1l, :for propelling broaches through =worl 'Y supported :on the These heads constitutey :the fmovling element of a machine tool, whose `,tra-vel is to be controlledby the belt shift mechanism. They are mounted on verticalscrew threaded shafts 14 which reciprocate up and down according as the worm gears 16 and rotatable nuts 18 at the top are revolved in one direction or another by the horizontal worm 20 between them. This worm is fixed on the drive shaft 22 which extends rear ward of the head. carryingthree pulleys, 24, 26 and 28, of which the outside two 24 and 28 are loose thereon and the middle one 26 is tight. Two belts (passing through cages 54, 56, but not shown), one stra1ght and the other crossed, run oppositely on the two loose pulleys when the machine is idle.'

Upon the shifting of either belt to the middle pulley the worm or drive shaft 22 is rotated in accordance with the direction of. travel of the belt so shifted.

It is a feature of the invention to provide a combined hand and automatic control for shifting the belts. To this end there is a hand lever 80 provided with a detent pin 32 which acting` as a latch under pressure of a coiled spring 84 engages holes 86 in a fixed sector plate so that when the lever is moved by the operator it will normally be stopped by the detent pin at a predetermined position in its swing, which is correct for the belt drive, and held there until dislodged by sufficient force, such as may be applied by the breaching head, or by hand, at the end of desired travel. The fulcrum of this hand lever is shaft 38. upon which the arm 80 is fixed, and to which its other arm 40 is also fast. The latter is linked through a vertical rod 42 (upon which are dogs, 44. 46.v adjustable in the path of the broach head Yl() to determine its upper and lower limits of travel) to an approximately horizontal arm 48n of a bell crank lever 48 whose 'fulcrum is a shaft 50 in fixture 52 holding the pulleys on the rear of the machine. The axis of shaft 50 is perpendicular to that of the drive shaft 22 and the pulleys. so that the vertical arm 48b of this bell crank swings alongside the drive shaft in direction to shift the belts. Such swinging occurs whenever the rod 42 is moved by the handle 80 or by either dog 44 or 46.

However. the bell crank 48 does not shift the belts directly. Instead it operates the belt cages 54 and 56 through lost motion connections. Vhen the handle 30 and arm 48 rise, the belt cage 54 moves a belt from pulley 24, to drive the broach head down, and when said handle and arm go down, the belt cage 56 moves another belt from pulley 28 to drive the broach head up. Moreover it does not positively shift either of these belts off from the drive pulley 26, that function being performed by` power which is stored in a spring 58 when the belt is moved to the drive pulley by the bell crank 48. This spring is too weak to act eXcept when the detent 82 is disengaged as herein eX- plained, which occurs whenever the bell crank is by hand or machine power swung back from either setting position.

Normally the belt is shifted to driving position by the hand of the operator, and is shifted from it by the power of said spring, and therefore is always removed with a suitably gentle touch. without the speed at which the machine throws the bell crank ont of thc way determining the speed of travel of the belt. Moreover, by this said device. details of which are hereinafter described, it is pro vided that each belt tends always to return to and stay on its loose pulley, whenever not latched on the drive pulley. and this makes it safe to have the lost motion in its connections, which permits of using single width pulleys` and has other advantages.

The belt cage 54 is on a lever 6() which extends thence down to below its loose fulcrum on shaft 50 (which shaft is also the fulcrum of the bell crank 48). Above its .fulcrum the lever 60 is engaged and moved at times by the lng 62 on bell crank lever 48 when the latter pushes it into drivingr position as seen in Figure 4. Below the fulcrum the lever is attached to a spring 58 which constantly pulls the lever toward its loose pulley position seen in Figures l and 5. but actually moves it thither only when the lug 62 permits.

The belt cage 56 is on the other side of the pulley 28. on a lever 63 which is more or less concealed by other parts in the drawing. In Figure 2 it is seen extending downward to its fulcrum or shaft 64, which in this ligure is directly behind shaft .'30, except that shaft 64 extends a little further to the left than shaft 50. which ends at collar 66. This fulcrum 64 extends through to the right side of the pulleys and there carries a lever 68 with arms marked 68a and 68b extending respectively downward to the spring 58 and upward to a link 70. These would ordinarily be mostly concealed by levers 48 and 60 in Figure 2, but for the sake of making them visible they are there represented as being slightly larger than those levers and curved on different lines. This lever 68 is actuated by the link 70, to set its belt in driving position. when said link is pulled by the bell crank lever 48, on which occasions it shifts from the position of Figure l to that of Figure 5; and is'actuated by spring 58 to restore the belt to loose pulley 28 whenever the bell crank pull on link is relaxed by the return of the bell crank to the position of Figure l. The lostmotion provided by either slot 70 or 70" in this link permits the bell crank 48 to move to its position for drive in the opposite direction without moving the belt on the pulley 28. In the shifting device it will be seen that the connection of the shift operating devices, 30, 44. 46. to each belt cage 54 or 56. has lost motion when it is moving` either belt toward the other, so

that the other is not simultaneously pushed or pulled thereby in the same direction. Stop pins 7 2 prevent any such motion occurring accidentally or as a result of the pull of the spring 58.

In operation, the parts being at rest as in Figure l, the operator sets a piece of Work on the table 12 with its hole over the hole 12a and drops a push broach into it. He then raises the starting lever 30 by hand. This throws lug 62 to the right and produces the setting shown in Figure 4 shifting the belt from pulley 24 to 26, but the pin 74 moves freely in the slot 70a in link 70, and imparts no motionfto that link or the belt on pulley 28. This starts the down drive of the broach head 10. When the head reaches a point predetermined by the setting of dog 44, its engagement with said dog depresses rod 42, pulling the bell crank lever 48 back to Figure l position and in so doing pulley lug 62 away from the lever 60. This allows spring 58 to pull the belt back to the loose pulley 24 without affecting belt lever 68; and the machine stops. To start travel of the head in reverse direction the operator depresses the lever 80. As the pins 74, 7 6 are already at the opposite extremities of the slots provided in link 70, the pull of the bell crank 48 which accompanies this depression, pulls link 70 and lever 68 to the left to the position of Figure 5, with lug 62 moving away Vfrom lever and therefore not affecting it. The head starts upward and continues in motion until it engages the dog 46 and restores the bell crank to the position of Figure 1 and stops the machine. Either one of the slots in link may be omitted.

The mechanism described provides a machine that cannot be started except by the operator, but which may be stopped either by him or by the automatic mechanical means. The operator need not concern himself with the stopping, and. can give his entire attention to other matters about the machine, or elsewhere, while the machine is in operation. This insures that there shall be no inadvertent over-travel, with damage that might result therefrom.

I claim as my invention:

l. A belt shifting mechanism for controlling the rotation of a drive shaft, comprising a pulley tight thereon and one loose thereon on each side of it, and apparatus for moving the belt of each loose pulley to the tight pulley; said apparatus comprising a pair of levers one lfor each belt, fulcrumed on separate axes and separately movable to shift said belts; a third lever, fulcrumed on the same axis with one of the belt shifting levers and having a lug arranged to engage and to move one of the belt-shifting levers toward the tight pulley when said third lever is swung in one direction, there being spring means holding the other belt-shifting lever against shifting, and for returning said belt shifting lever to its loose pulley position when said lug is withdrawn from engagement therewith.

A2. A belt shifting mechanism for controlling the rotation of a drive shaft; comprising three adjacent pulleys thereon, the two outside ones being loose and the middle one tight, and apparatus for moving the belt vfrom each loose pulley to the tight pulley; said apparatus comprising a pair of levers fulcrumed on separate axes and separately movable to shift said belts; a third lever, fulcrumed on the axis of one of them; and a link connecting said third lever with the other of them, whereby upon the thirdv lever being swung away from the tight pulley, said other is moved toward the tight pulley to shift its belt thereon; there being a pin and slot connection between said link and one of the levers it connects, whereby the said third lever may return to its first position without forcing said other lever back to its loose pulley position; and spring means for vreturning said other lever to its pulley position when said third lever has been moved back to its initial position.

3. A power control mechanism comprising a drive shaft having two pulleys loose thereon and a driving pulley fast thereon between the loose pulleys; means for shifting a belt between each loose pulley and the fast pulley; comprising a pair of parallel levers; stops for the levers limiting the swing of each away from the fast pulley, spring means connecting the levers and reacting against the stop of one lever to impel the other lever to its stop whenever such other lever is in drive position; and yieldable means stronger than said spring for holding the lever in drive position; whereby the spring returns the lever to loose pulley position when said stronger means is overcome.

Signed at Dayton, Ohio, this 28th day of July, 1924.l

MATTEO E. INFIORATI, JR. 

